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2022-03-15x86: Remove toolchain check for X32 ABI capabilityMasahiro Yamada10-48/+28
Commit 0bf6276392e9 ("x32: Warn and disable rather than error if binutils too old") added a small test in arch/x86/Makefile because binutils 2.22 or newer is needed to properly support elf32-x86-64. This check is no longer necessary, as the minimum supported version of binutils is 2.23, which is enforced at configuration time with scripts/min-tool-version.sh. Remove this check and replace all uses of CONFIG_X86_X32 with CONFIG_X86_X32_ABI, as two symbols are no longer necessary. [nathan: Rebase, fix up a few places where CONFIG_X86_X32 was still used, and simplify commit message to satisfy -tip requirements] Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220314194842.3452-2-nathan@kernel.org
2022-03-15x86/alternative: Use .ibt_endbr_seal to seal indirect callsPeter Zijlstra8-13/+117
Objtool's --ibt option generates .ibt_endbr_seal which lists superfluous ENDBR instructions. That is those instructions for which the function is never indirectly called. Overwrite these ENDBR instructions with a NOP4 such that these function can never be indirect called, reducing the number of viable ENDBR targets in the kernel. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154319.822545231@infradead.org
2022-03-15objtool: Find unused ENDBR instructionsPeter Zijlstra4-2/+78
Find all ENDBR instructions which are never referenced and stick them in a section such that the kernel can poison them, sealing the functions from ever being an indirect call target. This removes about 1-in-4 ENDBR instructions. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154319.763643193@infradead.org
2022-03-15objtool: Validate IBT assumptionsPeter Zijlstra4-5/+215
Intel IBT requires that every indirect JMP/CALL targets an ENDBR instructions, failing this #CP happens and we die. Similarly, all exception entries should be ENDBR. Find all code relocations and ensure they're either an ENDBR instruction or ANNOTATE_NOENDBR. For the exceptions look for UNWIND_HINT_IRET_REGS at sym+0 not being ENDBR. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154319.705110141@infradead.org
2022-03-15objtool: Add IBT/ENDBR decodingPeter Zijlstra2-5/+30
Intel IBT requires the target of any indirect CALL or JMP instruction to be the ENDBR instruction; optionally it allows those two instructions to have a NOTRACK prefix in order to avoid this requirement. The kernel will not enable the use of NOTRACK, as such any occurence of it in compiler generated code should be flagged. Teach objtool to Decode ENDBR instructions and WARN about NOTRACK prefixes. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154319.645963517@infradead.org
2022-03-15objtool: Read the NOENDBR annotationPeter Zijlstra2-3/+37
Read the new NOENDBR annotation. While there, attempt to not bloat struct instruction. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154319.586815435@infradead.org
2022-03-15x86: Annotate idtentry_df()Peter Zijlstra1-0/+3
Without CONFIG_X86_ESPFIX64 exc_double_fault() is noreturn and objtool is clever enough to figure that out. vmlinux.o: warning: objtool: asm_exc_double_fault()+0x22: unreachable instruction 0000000000001260 <asm_exc_double_fault>: 1260: f3 0f 1e fa endbr64 1264: 90 nop 1265: 90 nop 1266: 90 nop 1267: e8 84 03 00 00 call 15f0 <paranoid_entry> 126c: 48 89 e7 mov %rsp,%rdi 126f: 48 8b 74 24 78 mov 0x78(%rsp),%rsi 1274: 48 c7 44 24 78 ff ff ff ff movq $0xffffffffffffffff,0x78(%rsp) 127d: e8 00 00 00 00 call 1282 <asm_exc_double_fault+0x22> 127e: R_X86_64_PLT32 exc_double_fault-0x4 1282: e9 09 04 00 00 jmp 1690 <paranoid_exit> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/Yi9gOW9f1GGwwUD6@hirez.programming.kicks-ass.net
2022-03-15x86,objtool: Move the ASM_REACHABLE annotation to objtool.hPeter Zijlstra5-7/+34
Because we need a variant for .S files too. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/Yi9gOW9f1GGwwUD6@hirez.programming.kicks-ass.net
2022-03-15x86: Annotate call_on_stack()Peter Zijlstra1-1/+2
vmlinux.o: warning: objtool: page_fault_oops()+0x13c: unreachable instruction 0000 000000000005b460 <page_fault_oops>: ... 0128 5b588: 49 89 23 mov %rsp,(%r11) 012b 5b58b: 4c 89 dc mov %r11,%rsp 012e 5b58e: 4c 89 f2 mov %r14,%rdx 0131 5b591: 48 89 ee mov %rbp,%rsi 0134 5b594: 4c 89 e7 mov %r12,%rdi 0137 5b597: e8 00 00 00 00 call 5b59c <page_fault_oops+0x13c> 5b598: R_X86_64_PLT32 handle_stack_overflow-0x4 013c 5b59c: 5c pop %rsp vmlinux.o: warning: objtool: sysvec_reboot()+0x6d: unreachable instruction 0000 00000000000033f0 <sysvec_reboot>: ... 005d 344d: 4c 89 dc mov %r11,%rsp 0060 3450: e8 00 00 00 00 call 3455 <sysvec_reboot+0x65> 3451: R_X86_64_PLT32 irq_enter_rcu-0x4 0065 3455: 48 89 ef mov %rbp,%rdi 0068 3458: e8 00 00 00 00 call 345d <sysvec_reboot+0x6d> 3459: R_X86_64_PC32 .text+0x47d0c 006d 345d: e8 00 00 00 00 call 3462 <sysvec_reboot+0x72> 345e: R_X86_64_PLT32 irq_exit_rcu-0x4 0072 3462: 5c pop %rsp Both cases are due to a call_on_stack() calling a __noreturn function. Since that's an inline asm, GCC can't do anything about the instructions after the CALL. Therefore put in an explicit ASM_REACHABLE annotation to make sure objtool and gcc are consistently confused about control flow. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154319.468805622@infradead.org
2022-03-15objtool: Rework ASM_REACHABLEPeter Zijlstra1-13/+20
Currently ASM_REACHABLE only works for UD2 instructions; reorder things to also allow over-riding dead_end_function(). To that end: - Mark INSN_BUG instructions in decode_instructions(), this saves having to iterate all instructions yet again. - Have add_call_destinations() set insn->dead_end for dead_end_function() calls. - Move add_dead_ends() *after* add_call_destinations() such that ASM_REACHABLE can clear the ->dead_end mark. - have validate_branch() only check ->dead_end. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154319.410010807@infradead.org
2022-03-15x86: Mark __invalid_creds() __noreturnPeter Zijlstra3-2/+3
vmlinux.o: warning: objtool: ksys_unshare()+0x36c: unreachable instruction 0000 0000000000067040 <ksys_unshare>: ... 0364 673a4: 4c 89 ef mov %r13,%rdi 0367 673a7: e8 00 00 00 00 call 673ac <ksys_unshare+0x36c> 673a8: R_X86_64_PLT32 __invalid_creds-0x4 036c 673ac: e9 28 ff ff ff jmp 672d9 <ksys_unshare+0x299> 0371 673b1: 41 bc f4 ff ff ff mov $0xfffffff4,%r12d 0377 673b7: e9 80 fd ff ff jmp 6713c <ksys_unshare+0xfc> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/Yi9gOW9f1GGwwUD6@hirez.programming.kicks-ass.net
2022-03-15exit: Mark do_group_exit() __noreturnPeter Zijlstra3-2/+3
vmlinux.o: warning: objtool: get_signal()+0x108: unreachable instruction 0000 000000000007f930 <get_signal>: ... 0103 7fa33: e8 00 00 00 00 call 7fa38 <get_signal+0x108> 7fa34: R_X86_64_PLT32 do_group_exit-0x4 0108 7fa38: 41 8b 45 74 mov 0x74(%r13),%eax Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154319.351270711@infradead.org
2022-03-15x86: Mark stop_this_cpu() __noreturnPeter Zijlstra3-2/+3
vmlinux.o: warning: objtool: smp_stop_nmi_callback()+0x2b: unreachable instruction 0000 0000000000047cf0 <smp_stop_nmi_callback>: ... 0026 47d16: e8 00 00 00 00 call 47d1b <smp_stop_nmi_callback+0x2b> 47d17: R_X86_64_PLT32 stop_this_cpu-0x4 002b 47d1b: b8 01 00 00 00 mov $0x1,%eax Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154319.290905453@infradead.org
2022-03-15objtool: Ignore extra-symbol codePeter Zijlstra3-0/+104
There's a fun implementation detail on linking STB_WEAK symbols. When the linker combines two translation units, where one contains a weak function and the other an override for it. It simply strips the STB_WEAK symbol from the symbol table, but doesn't actually remove the code. The result is that when objtool is ran in a whole-archive kind of way, it will encounter *heaps* of unused (and unreferenced) code. All rudiments of weak functions. Additionally, when a weak implementation is split into a .cold subfunction that .cold symbol is left in place, even though completely unused. Teach objtool to ignore such rudiments by searching for symbol holes; that is, code ranges that fall outside the given symbol bounds. Specifically, ignore a sequence of unreachable instruction iff they occupy a single hole, additionally ignore any .cold subfunctions referenced. Both ld.bfd and ld.lld behave like this. LTO builds otoh can (and do) properly DCE weak functions. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154319.232019347@infradead.org
2022-03-15objtool: Rename --duplicate to --ltoPeter Zijlstra4-5/+10
In order to prepare for LTO like objtool runs for modules, rename the duplicate argument to lto. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154319.172584233@infradead.org
2022-03-15x86/ibt: Ensure module init/exit points have referencesPeter Zijlstra1-1/+10
Since the references to the module init/exit points only have external references, a module LTO run will consider them 'unused' and seal them, leading to an immediate fail on module load. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154319.113767246@infradead.org
2022-03-15x86/ibt: Dont generate ENDBR in .discard.textPeter Zijlstra1-1/+2
Having ENDBR in discarded sections can easily lead to relocations into discarded sections which the linkers aren't really fond of. Objtool also shouldn't generate them, but why tempt fate. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154319.054842742@infradead.org
2022-03-15x86/ibt,sev: AnnotationsPeter Zijlstra3-0/+4
No IBT on AMD so far.. probably correct, who knows. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154318.995109889@infradead.org
2022-03-15x86/ibt,ftrace: Annotate ftrace code patchingPeter Zijlstra1-0/+7
These are code patching sites, not indirect targets. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154318.936599479@infradead.org
2022-03-15x86/ibt: Annotate text referencesPeter Zijlstra8-2/+25
Annotate away some of the generic code references. This is things where we take the address of a symbol for exception handling or return addresses (eg. context switch). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154318.877758523@infradead.org
2022-03-15x86/ibt: Disable IBT around firmwarePeter Zijlstra4-2/+48
Assume firmware isn't IBT clean and disable it across calls. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154318.759989383@infradead.org
2022-03-15x86/alternative: Simplify int3_selftest_ipPeter Zijlstra1-14/+7
Similar to ibt_selftest_ip, apply the same pattern. Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154318.700456643@infradead.org
2022-03-15x86/ibt,kexec: Disable CET on kexecPeter Zijlstra4-1/+20
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154318.641454603@infradead.org
2022-03-15x86/ibt: Add IBT feature, MSR and #CP handlingPeter Zijlstra9-2/+133
The bits required to make the hardware go.. Of note is that, provided the syscall entry points are covered with ENDBR, #CP doesn't need to be an IST because we'll never hit the syscall gap. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154318.582331711@infradead.org
2022-03-15x86/ibt,ftrace: Add ENDBR to samples/ftracePeter Zijlstra5-4/+22
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154318.523421433@infradead.org
2022-03-15x86/ibt,bpf: Add ENDBR instructions to prologue and trampolinePeter Zijlstra1-2/+24
With IBT enabled builds we need ENDBR instructions at indirect jump target sites, since we start execution of the JIT'ed code through an indirect jump, the very first instruction needs to be ENDBR. Similarly, since eBPF tail-calls use indirect branches, their landing site needs to be an ENDBR too. The trampolines need similar adjustment. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Fixed-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154318.464998838@infradead.org
2022-03-15x86/ibt,kprobes: Cure sym+0 equals fentry woesPeter Zijlstra4-28/+92
In order to allow kprobes to skip the ENDBR instructions at sym+0 for X86_KERNEL_IBT builds, change _kprobe_addr() to take an architecture callback to inspect the function at hand and modify the offset if needed. This streamlines the existing interface to cover more cases and require less hooks. Once PowerPC gets fully converted there will only be the one arch hook. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154318.405947704@infradead.org
2022-03-15x86/ibt,ftrace: Make function-graph play nicePeter Zijlstra2-11/+19
Return trampoline must not use indirect branch to return; while this preserves the RSB, it is fundamentally incompatible with IBT. Instead use a retpoline like ROP gadget that defeats IBT while not unbalancing the RSB. And since ftrace_stub is no longer a plain RET, don't use it to copy from. Since RET is a trivial instruction, poke it directly. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154318.347296408@infradead.org
2022-03-15x86/livepatch: Validate __fentry__ locationPeter Zijlstra2-27/+2
Currently livepatch assumes __fentry__ lives at func+0, which is most likely untrue with IBT on. Instead make it use ftrace_location() by default which both validates and finds the actual ip if there is any in the same symbol. Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154318.285971256@infradead.org
2022-03-15x86/ibt,ftrace: Search for __fentry__ locationPeter Zijlstra4-39/+48
Currently a lot of ftrace code assumes __fentry__ is at sym+0. However with Intel IBT enabled the first instruction of a function will most likely be ENDBR. Change ftrace_location() to not only return the __fentry__ location when called for the __fentry__ location, but also when called for the sym+0 location. Then audit/update all callsites of this function to consistently use these new semantics. Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154318.227581603@infradead.org
2022-03-15x86/ibt,kvm: Add ENDBR to fastopsPeter Zijlstra1-2/+4
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154318.168850084@infradead.org
2022-03-15x86/ibt,crypto: Add ENDBR for the jump-table entriesPeter Zijlstra1-0/+3
The code does: ## branch into array mov jump_table(,%rax,8), %bufp JMP_NOSPEC bufp resulting in needing to mark the jump-table entries with ENDBR. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154318.110500806@infradead.org
2022-03-15x86/ibt,paravirt: Sprinkle ENDBRPeter Zijlstra4-1/+8
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154318.051635891@infradead.org
2022-03-15x86/linkage: Add ENDBR to SYM_FUNC_START*()Peter Zijlstra1-0/+31
Ensure the ASM functions have ENDBR on for IBT builds, this follows the ARM64 example. Unlike ARM64, we'll likely end up overwriting them with poison. Suggested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154317.992708941@infradead.org
2022-03-15x86/ibt,entry: Sprinkle ENDBR dustPeter Zijlstra6-13/+29
Kernel entry points should be having ENDBR on for IBT configs. The SYSCALL entry points are found through taking their respective address in order to program them in the MSRs, while the exception entry points are found through UNWIND_HINT_IRET_REGS. The rule is that any UNWIND_HINT_IRET_REGS at sym+0 should have an ENDBR, see the later objtool ibt validation patch. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154317.933157479@infradead.org
2022-03-15x86/ibt,xen: Sprinkle the ENDBRPeter Zijlstra6-3/+22
Even though Xen currently doesn't advertise IBT, prepare for when it will eventually do so and sprinkle the ENDBR dust accordingly. Even though most of the entry points are IRET like, the CPL0 Hypervisor can set WAIT-FOR-ENDBR and demand ENDBR at these sites. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154317.873919996@infradead.org
2022-03-15x86/entry,xen: Early rewrite of restore_regs_and_return_to_kernel()Peter Zijlstra7-15/+17
By doing an early rewrite of 'jmp native_iret` in restore_regs_and_return_to_kernel() we can get rid of the last INTERRUPT_RETURN user and paravirt_iret. Suggested-by: Andrew Cooper <Andrew.Cooper3@citrix.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154317.815039833@infradead.org
2022-03-15x86/entry: Cleanup PARAVIRTPeter Zijlstra1-2/+2
Since commit 5c8f6a2e316e ("x86/xen: Add xenpv_restore_regs_and_return_to_usermode()") Xen will no longer reach this code and we can do away with the paravirt SWAPGS/INTERRUPT_RETURN. Suggested-by: Andrew Cooper <Andrew.Cooper3@citrix.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154317.756014488@infradead.org
2022-03-15x86/ibt,paravirt: Use text_gen_insn() for paravirt_patch()Peter Zijlstra2-26/+17
Less duplication is more better. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154317.697253958@infradead.org
2022-03-15x86/text-patching: Make text_gen_insn() play nice with ANNOTATE_NOENDBRPeter Zijlstra1-1/+9
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154317.638561109@infradead.org
2022-03-15x86/ibt: Add ANNOTATE_NOENDBRPeter Zijlstra2-0/+32
In order to have objtool warn about code references to !ENDBR instruction, we need an annotation to allow this for non-control-flow instances -- consider text range checks, text patching, or return trampolines etc. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154317.578968224@infradead.org
2022-03-15x86/ibt: Base IBT bitsPeter Zijlstra3-2/+121
Add Kconfig, Makefile and basic instruction support for x86 IBT. (Ab)use __DISABLE_EXPORTS to disable IBT since it's already employed to mark compressed and purgatory. Additionally mark realmode with it as well to avoid inserting ENDBR instructions there. While ENDBR is technically a NOP, inserting them was causing some grief due to code growth. There's also a problem with using __noendbr in code compiled without -fcf-protection=branch. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154317.519875203@infradead.org
2022-03-15objtool: Have WARN_FUNC fall back to sym+offPeter Zijlstra1-0/+2
Currently WARN_FUNC() either prints func+off and failing that prints sec+off, add an intermediate sym+off. This is useful when playing around with entry code. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154317.461283840@infradead.org
2022-03-15objtool,efi: Update __efi64_thunk annotationPeter Zijlstra2-3/+4
The current annotation relies on not running objtool on the file; this won't work when running objtool on vmlinux.o. Instead explicitly mark __efi64_thunk() to be ignored. This preserves the status quo, which is somewhat unfortunate. Luckily this code is hardly ever used. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154317.402118218@infradead.org
2022-03-15objtool: Default ignore INT3 for unreachablePeter Zijlstra1-7/+5
Ignore all INT3 instructions for unreachable code warnings, similar to NOP. This allows using INT3 for various paddings instead of NOPs. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154317.343312938@infradead.org
2022-03-15objtool: Add --dry-runPeter Zijlstra3-2/+6
Add a --dry-run argument to skip writing the modifications. This is convenient for debugging. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154317.282720146@infradead.org
2022-03-15static_call: Avoid building empty .static_call_sitesPeter Zijlstra1-0/+4
Without CONFIG_HAVE_STATIC_CALL_INLINE there's no point in creating the .static_call_sites section and it's related symbols. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154317.223798256@infradead.org
2022-03-15Merge branch 'arm64/for-next/linkage'Peter Zijlstra27-163/+172
Enjoy the cleanups and avoid conflicts vs linkage Signed-off-by: Peter Zijlstra <peterz@infradead.org>
2022-03-15tools/objtool: Check for use of the ENQCMD instruction in the kernelFenghua Yu1-1/+10
The ENQCMD instruction implicitly accesses the PASID_MSR to fill in the pasid field of the descriptor being submitted to an accelerator. But there is no precise (and stable across kernel changes) point at which the PASID_MSR is updated from the value for one task to the next. Kernel code that uses accelerators must always use the ENQCMDS instruction which does not access the PASID_MSR. Check for use of the ENQCMD instruction in the kernel and warn on its usage. Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Tony Luck <tony.luck@intel.com> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220207230254.3342514-11-fenghua.yu@intel.com Signed-off-by: Peter Zijlstra <peterz@infradead.org>
2022-03-13Linux 5.17-rc8v5.17-rc8Linus Torvalds1-1/+1
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-26 12:08:10 +0300